Means for chlorinating swimming pools

ABSTRACT

Apparatus for sanitizing swimming pools in which the sanitizing agent such as chlorine-containing powder or tablets is metered into circulating water to avoid undue concentrations of agent in water. The treated water is withdrawn to the pool and not permitted to stand in the lines between filtering cycles. separately valved inlet and outlet ports in the agent-water mixing chamber are opened or closed by independent floats which maintain a desired water level in the mixing chamber during water circulation and enables closing of the chamber outlet after gravity draining of water from the chamber.

I United States Patent 1151 3,638,833 Lucas Feb. 1, 1972 [54] MEANS FORCHLORINATING 3,171,449 3/1965 Ellms et a1. ..222/83.5 SWIMMING POOLS2,761,562 9/1956 Moody ..23/267 E 1,216,051 21917 B l ..23 [72]Inventor: Robert S. Lucas, Harbor City, Calif. 3 094 '34 41963 32: 5[73] Assignee: Purex Corporation, Ltd., Lakewood, Calif. 3,507,624 4/1970 Schneider et al. ..239/310 X [22] Filed. Primary ExaminerStanley H.Tollberg [21] Appl.No.: 9,900 Assistant Examiner-Larry MartinAttorney-White, Haefliger & Bachand [52] U.S. Cl ..222/57, 23/267 E,210/123,

137/268, 222/67, 222/448 [57] ABSTRACT [51 lllt- Apparatus for anitizingswimming pools in [he anitiz. Fleld 0 Search 57, agent such as chloine.containing powder or tablets is me. 222/365, 83-5, 88; 37/268;23/267 tered into circulating water to avoid undue concentrations of272-8; 210/119 134; 251/9 agent in water. The treated water is withdrawnto the pool and not permitted to stand in the lines between filteringcycles. [56] References cued separately valved inlet and outlet ports inthe agent-water mix- UNITED STATES PATENTS ing cha mber are opened orclosed by independent floats which maintain a desired water level in themixing chamber dunng 3,406,870 10/1968 Amesonm 222/67 X watercirculation and enables closing of the chamber outlet 2,698,292 12/l95421023 X after gravity draining ofwater from the chamber. 3,356,46012/1967 King et al.. ..251/9 3,128,915 4/ 1964 Matter ..222/448 X 14Claims, 6 Drawing Figlres MEANS FOR CHLORINATING SWIMMING POOLSBACKGROUND OF THE INVENTION 1. Field of the Invention This invention hasto do with swimming pool maintenance. To be healthful, swimming poolsmust be maintained free of bacteria which are introduced through use ofthe pool and by exposure of the pool to the environment. Thus,maintenance is a continuing effort. The periodic addition of sanitizingchemicals is the most popular way to maintain satisfactory bacterialevels in swimming pools. The action of the sun and other factors suchas heat operate to destroy added chemicals and fresh quantities must beadded. To do so the pool owner pours liquid hypochlorite solution intothe pool or tosses one or more packets of powdered sanitizing agente.g., sodium trichlorocyanurate, into the pool. In either case personalattention of the owner is required and care must be taken to getaccurate dosage and to avoid harmful contact with skin or clothing ofstrong chemicals or even their vapors.

2. Prior Art More recently devices have been provided whichautomatically add sanitizing chemicals to swimming pool water. Thesedevices are generally adapted to deliver chlorinating, brominating orother active product to the water circulation system normally associatedwith a swimming pool as a part of the filtering system. These filteringsystems operate for a greater or lesser part of each day andaccordingly, there is a rise and fall of water pressure downstream ofthe pump which circulates water for filtering.

In US. Pat. No. 3,406,870 to Arneson, a device is disclosed which has acommon inlet and outlet to a mixing chamber for water and chlorinatingor other powdered agent. Upon start up of the filter cycle circulationwater enters the mixing chamber, rising up to a predetermined levelwhich serves to meter chlorinating agent from a larger supply into themixing chamber. Upon shutdown of the water circulation system, thehighly concentrated chlorine bearing solution drains through the outletinto the circulation system where it lies until the pump is restarted,usually many hours later. The continuing presence of corrosive chemicalsolutions in piping is not desirable and is to be avoided, if possible.

Other workers in the art have developed automatic chlorinators whichdump metered amounts of chlorine-bearing powders into a circulatingstream, thus overcoming the undue solution concentration problem, if thechlorine-containing solution is not generated or retained in the mixingchamber between circulation periods. Thus far, however, circulating typeautomatic chlorinators have employed rocker arm valves to oppositelyopen and close the inlet and outlet ports. A float arm connected to therocker arm closes the inlet when high and closes the outlet when low,all to maintain the water level in the chamber within a close range. Atthe desired level, both inlet and outlet are open, inflow and outfloware balanced and the water contacts a supply of controllably solublechlorinating powder partly immersed in the water, thus to meter agentinto the water. Upon shutdown of the pump, a slight drop in water in thechamber which may still leave the water in contact with the chlorinatingpowder, occurs and the outlet immediately closes. The water in thechamber with chlorine material dissolved therein is trapped until thenext cycle whereupon it is initially discharged into the loop pipingwhere it may be harmfully corrosive before being flushed with additionalwater back to the pool.

SUMMARY OF THE INVENTION It is a major objective of the invention toprovide an automatic chlorinator in which the chlorine-bearing powderedmaterial or other sanitizing chemical is dissolved in a circulatingwater stream and at the onset of the water circulation cycle and inwhich the mixed water is drained by gravity from the mixing chamber atthe end of the circulation cycle substantially free of chlorine or otheraggressive sanitizing chemical so that sporadic introduction of highlyconcentrated chemical solutions into the circulation loop piping isavoided.

The invention provides apparatus for sanitizing swimming pool waterwhich includes a mixing chamber having an inlet port and a relativelylower outlet port all above the swimming pool to be sanitized, meansperiodically circulating pool water through the chamber including a pumpand conduit leading to and from the pool, the circulating meansintroducing water from the conduit on the discharge side of the pump tothe chamber through the inlet port and withdrawing water from thechamber through the outlet port to conduit on the suction side of thepump. The apparatus further includes means introducing a meteredquantity of normally solid water soluble sanitizing agent in response toperiodic water circulation through the chamber for mixing with water atthe onset of the water circulation period.

Such means may include a supply chamber containing a supply of thesanitizing agent and having a bottom opening vertically spaced above themixing chamber, a metering cup open to and below the mixing chamberopening, valve means movable between the openings to sequentiallycommunicate the supply chamber with the metering cup and the meteringcup with the mixing chamber to deliver metered amounts of agent from thesupply to the mixing chamber, The valve means may comprise a pair ofvalve members vertically spaced a distance to be movable selectivelyinto alternate blocking relation with one or the other of the bottomopenings and float means in the mixing chamber connected to the valvemembers to raise or lower the valve members together in response towater level changes in the mixing chamber, to first charge the meteringcup from the supply chamber at the onset of water circulation and toempty the metering cup into the mixing chamber following the watercirculation period and after water has substantially completely drainedtherefrom.

Alternatively, the sanitizing agent introducing means may include asupply of the agent disposed in an elongated container which is mountedvertically on the top wall of the mixing chamber in a manner to have alower container portion submerged in water periodically circulatedthrough the chamber and out of contact with water when water circulationceases and an upper container portion above the water as a continuationof the lower portion, the submerged container portion having a waterpassing aperture permitting dissolution and dispersal of agent from thelower container portion, the agent in the upper portion being arrangedto descend by gravity to continually replace dissolved and dispersedagent in the lower portion.

Two independent valve means are provided in the chamber separatelycontrolling water flow through the inlet and the outlet including afirst float-controlled inlet valve operative to limit the level of waterin the chamber during water circulation periods and a secondfloat-controlled outlet valve operative to maintain the outlet open topermit substantially complete gravity draining of water from the chamberfollowing termination of the water circulation period and thereafter toclose the outlet valve.

BRIEF DESCRIPTION OF THE DRAWINGS The invention will be furtherdescribed as to specific illustrative embodiments in connection with theattached drawings in which:

FIG. I is a vertical section view of an automatic sanitizing deviceaccording to the invention in its mode following completion of the watercirculation period and draining of the device;

FIG. 2 is an enlarged view partly in elevation of the open inlet valveshown in FIG. 1;

FIG. 3 is a view like FIG. 1 and showing the automatic sanitizing devicein the maximum fill condition during the water circulation period;

FIG. 4 is a view like FIG. 2 and showing enlarged the inlet valve ofFIG. 3;

FIG. 5 is a view generally similar to FIG. 1 of an alternate form of thedevice particularly as to the powder-introductive means; and

FIG. 6 is a view in section taken along line 6-6 in FIG. and enlarged,of the outlet valve and associated float control.

DESCRIPTION OF THE PREFERRED EMBODIMENTS With reference to the attacheddrawings and particularly FIGS. 1-4, there is shown an automatic poolwater sanitizing device D connected across water recirculation systempump P which comprises conduit 1 leading from the pool to the pump andconduit 2 which returns the water to the pool. Device D is connected tothe recirculation system conduit 1 and 2 by tubing 3 connected intoconduit 2 on the discharge or pressure side of pump P and tubing 4connected into conduit 1 on the intake or suction side of the pump.Device D is thus connected in a side stream having countercurrent flowto the main recirculation stream in conduit 1 and 2.

The device D comprises a housing 5 having a lower portion 6 defining amixing chamber 7 and an upper portion 8 housing sanitizing agentintroducing means 9 to be later described. Lower housing portion 6includes vertical sidewall 10 and horizontal bottom wall 11. A waterinlet 12 is provided through sidewall 10 and a water outlet 13 isprovided adjacent bottom wall 11. An overflow drain port 14 is providedabove the normal water level 15 (FIG. 3). Fitting 16 comprising threadedannular stem 17 which connects to tubing 18 is fixed in the overflowdrain port 14 by means of hexagonal nut 19 in the chamber 7 and wingnut20 outside the chamber. Tubing 18 is secured to stem 16 with ribbedcollar 21 threaded onto the stem.

The water inlet port 12 is provided with a fitting 22 comprising athreaded annular stem 23 having a nozzle 24 formed in tegrally therewithto project into chamber 7 when the stem is secured in the inlet port bywingnut 25 outside the wall 10 and U-bracket 26 inside the wall. As withthe drain port fitting 16 the inlet port 22 has an internally threadedcollar 27 which secures tubing 3 to the stem 23 whereby conduit 2 iscommunicated with chamber 7 through inlet port 12. U-bracket 26comprises a base 28 mounted flat against the wall 10 within the chamber7 and a pair of parallel ears 29 normal to the base. A shaft 30 extendsbetween the ears 29 slightly below and beyond nozzle 24 and parallel tothe base 28. A rocker arm 31 is mounted on the shaft 30 to pivottherearound. The arm 31 has a valve surface 32 in the form of resiliente.g., rubber disc 33 inset in the arm opposite nozzle 24 to engage thenozzle when the arm is rotated clockwise around the shaft 30. Acompression spring 34 is provided between strap 35 and arm 31 behinddisc 33 to urge the arm clockwise against the pressure of water enteringthe chamber through inlet nozzle 24. Rocker arm 31 movement iscontrolled by float 36 carried on rigid angle support 37 connected tothe rocker arm at 38. Float 36 is of buoyant material to be liftedupwardly by water in the chamber 7 (see FIG. 3) thereby to cause rockerarm 31 to rotate clockwise toward the nozzle 24 ultimately to close offthe nozzle when the water level is above that desired i.e., above theline 15 level. Accordingly, it will be seen that opening and closing ofinlet port 12 is responsive to the water level in chamber 7.

The outlet port 13 comprises beveled opening 39 in the rib 40 extendingfrom the middle point in chamber 7 to sidewall 10. Passage 41 formed inrib 40 leads from outlet port opening 39 to sidewall opening 42 andsecured there by nut 44 provides connection with tubing 4 communicatingwith suction conduit 1 and fastened to threaded stem 45 of the fittingwith not 46 and collar 47.

A second float 48 separate from and independently operative from thefloat 36 is provided in the chamber comprising buoyant material 49 andrigid cap 50. Vertical guides 51 positioned circumferentially aboutfloat 48 limit float movement to vertical travel. A resilient annularplug valve 52 suitably tapered endwise for smooth insertion into outletport opening 39 is carried by the float 48 to be above and verticallyaligned with the outlet port opening to enter and close the same whenthe float is in its downwardmost position. Rod 53 carrying valve body 54at its upper extent extends through cap and buoyant material 49 toprovide a projection 55 at its lower extent onto which the annular plugvalve 52 is secured. The bouyancy of the float 48 is such that when thechamber 7 is water filled the plug valve 52 is lifted off the outletport 13 to permit continuous water passage from the chamber (see FIG.3). After cessation of a water circulation period the float 48 remainsspaced above outlet port 13 as the water drains from chamber 7 until thesubstantially complete draining of water permits lowering of the plugvalve into the opening 39 of the outlet port 13. It will be noted thatno substantial amount of water is trapped within the chamber 7 and thatwhich remains is well out of contact with the sanitizing agent, as willnow be described.

With further reference to FIGS. 1 and 3 the valve system depicted may beused with a sanitizing agent introducing means 9 comprising a supplychamber 56 containing a supply of the sanitizing agent 57 e.g., normallysolid, water-soluble chlorine containing chemical powder such as sodiumor potassium dichloroisocyanurate, obtained from inverted container 58.Container 58 is a replaceable unit adapted for use with the presentlydisclosed chlorinators by threaded insertion of container neck 59 intoreceptacle 60 formed in generally conical cap 61. The container top maycomprise a severable membrane 62 e.g., of thin plastic which is cutcircularly by knife 63 mounted on support 64 within the receptacle 60e.g., about 300 as the container neck 59 is screwed into the receptacle.The membrane 62 then depends into the supply chamber 56. Completeseparation of the membrane 62 is not advisable since plugging of agentflow from the chamber may result.

The supply chamber 56 comprises a generally cylindrical upper wall 65and a conical lower wall 66 terminating in a bottom opening 67vertically spaced above the mixing chamber 7. An annular resilientsealing ring 68 is fitted in the bottom opening 67. Agent delivered fromcontainer 58 is stored in supply chamber 56 for passage through theopening 67.

Generally conical metering cup 69 is provided open to and below thesupply chamber 56 with its bottom opening 70 having annular sealing ring71 fitted therein, vertically below the supply chamber bottom opening 67and above the mixing chamber 7. The volume of metering cup 69 isvariable by vertical adjustment of the cup relative to the supplychamber lower wall 66. Adjustment may be made by loosening wingnuts 72on bolts 73 projecting radially from the metering cup 69 through opposedvertical adjustment slots 74 in upper portion 8 of the housing 5 raisingor lowering the cup and retightening the nuts. The metering cup 69 ismounted to slide vertically in annular channel 75 defined by circularprojection 76 extending downwardly from the cap 61 and the exterior ofupper wall 65 of the supply chamber 56 which is fitted onto smallerdiameter circular projection 77 also extending downward from the cap.Annular seals 78 and 79 are provided on the exteriors of the supplychamber 56 and metering cup 69 respectively to seal the supply chamber56 contents from water vapor in mixing chamber 7.

When the metering cup 69 has been adjusted to the desired volume and thesupply chamber 56 is filled with powdered sanitizing agent, verticalmovement of valve body 54 will sequentially communicate the supplychamber 56 with metering cup 69 and then metering cup 69 with mixingchamber 7 by movement of valve member surfaces 80 and 81 through theplanes of bottom openings 67 and 70 respectively. Thus, as seen in FIG.1, draining of water from mixing chamber 7 causes float 48 to settle tothe bottom of the chamber. This causes valve body 54 carried by rod 53on the float 48 to be lowered. The valve body 54 is sized to seal thebottom opening 67 in supply chamber 56 but it is provided at itsuppermost end with valving surface 80 which passes through the plane ofthe chamber opening 67 to permit powdered material 57 to flow intometering cup 69 in measured amount determined by the adjusted volume ofthe cup.

In FIG. 3, the water is at the operating maximum level and the float 48in the raised position. This causes valve body 54 to move upwardly untilbottom opening 70 in metering cup 69 is cleared by valving surface 81 ofthe valve bodyenabling powdered material 57 previously charged to themetering cup to fall into the water at 82 circulating through the mixingchamber 7. This metered deposit of sanitizing agent occurs at the onsetof water circulation by the pump P and not at its termination, so thatthe agent is thoroughly diluted and well delivered to the pool when thecirculating system is shut down, hours later. Of course, on againshutting off pump P, the metering process is repeated and a fresh chargeof sanitizing agent is admitted into the pool water on recommencement ofthe circulation cycle.

In FIG. 5 where like numerals indicate like parts in the precedingFigures, an alternate arrangement for sanitizing agent introduction isdepicted including an elongated cylindrical container 83 having ascrewcap 84 in which a supply of the agent 57 in tabletted form isdisposed. The container 83 is mounted vertically in the housing cap 611on housing 5 defining the mixing chamber 7 to have its lower portion 85submerged in the water 83 circulating through the mixing chamber byvirtue of the action of the pump P and the inlet and outlet port valves12 and 13 which operate as hereinbefore set forth. The container upperportion 86 extends above the water 82 as a continuation of the lowerportion 85. Waterpassing apertures 87 are provided in container lowerportion 85 to permit dissolution and dispersal of agent 57 disposedbelow the waterline 15. The smooth interior wall 88 of the container 83permits continual replacement of agent 57 dissolved from the lowercontainer portion 85 by gravity descent. The solubility of the tablettedagent is controlled to provide disintegration of the tablets over timeand thus, to provide a metered agent introduction into the water 82.

The upper portion 86 of the container is externally threaded at 89 tofacilitate vertical adjustment of the container lower portion 85 withrespect to the mixing chamber water level to allow more or lessincursion of water into the container lower portion, thus to limit orincrease dissolution of agent and its dispersal into the pool by pump Pthrough filter F.

The outlet port 13 best shown in FIG. 6 includes a boss 90 having aperipheral groove 91 and a central passage 92 communicating with passage41 in rib 40 leading to the suction conduit 1. Boss 90 is provided witha beveled opening 391 into which resilient valve 521 tapped into rod 531with screw 93 fits to close the opening 391 and the outlet port 13. RodS31 is supported by cage structure 94 anchored to boss 90 by inwardlyprojecting rib 95 in groove 91. Cage structure 94 has a top opening 96through which rod 531 projects. Float 481 comprises buoyant body 491centrally mounted on rod 531 with rod head 97.

It will be apparent that the elevational difference between inlet port12 and outlet port 13 ensures no water contact with agent when the pumpP is shut down unlike those systems where differences in water levelbetween the on and off conditions are minimal.

Iclaim:

1. Apparatus for sanitizing swimming pool water which includes a mixingchamber having an inlet port and a relatively lower outlet port allabove the swimming pool to be sanitized, means periodically circulatingpool water through the chamber including a pump and conduit leading toand from the pool, said means circulating water from conduit on thedischarge side of the pump to the chamber through said inlet portthrough said chamber and through the outlet port to conduit on thesuction side of the pump, means introducing a metered quantity ofnormally solid, water-soluble sanitizing agent into said chamber inresponse to periodic water circulation through the chamber for mixingwith water at the onset of the water circulation period to dissolve saidagent in water circulating through said chamber, two independent valvemeans in the chamber separately controlling waterflow through the inletand outlet ports including a first float-controlled inlet valveoperative to limit the level of water in the chamber during watercirculation periods and a second float-controlled outlet valve operativeto maintain the outlet open to permit substantially complete gravitydraining of water from the chamber following termination of the watercirculation period and thereafter to close the outlet valve.

2. Apparatus according to claim 1 in which said agent-introducing meansincludes a supply chamber containing a supply of the agent and having abottom opening vertically spaced above the mixing chamber, a meteringcup open to and below the supply chamber opening and having a bottomopening vertically below the supply chamber opening, valve means movablebetween said openings to sequentially communicate the supply chamberwith the metering cup and the metering cup with the mixing chamber todeliver metered amounts of agent from the supply to the mixing chamber,said valve means comprising a pair of valve members vertically spaced adistance to be movable into alternate blocking relation with one or theother of said bottom openings, and float means in said mixing chamberconnected to said valve members to raise or lower said valve membertogether in response to water level changes in said mixing chamber tofirst change the metering cup from the supply chamber at the onset ofthe water circulation period and to empty the metering cup into themixing chamber following the water circulation period and after waterhas substantially completely drained therefrom.

3. Apparatus according to claim 2 including also a resilient annularseal in each of said bottom openings and in which said valve meansincludes a cylindrical valve body having oppositely tapered upper andlower ends defining said valve members, said body having a diameter toslidably engage said seals.

4. Apparatus according to claim 3 in which said float means is alsooperatively connected to said outlet valve.

5. Apparatus according to claim 4 including also an agent supplycontainer and means carried on said supply chamber mounting saidcontainer to empty into said supply chamber, said mounting meansincluding an upwardly opening receptacle on top of said chamber adaptedto receive the neck of an inverted supply container.

6. Apparatus according to claim 5 in which said agent supply containerhas a top comprising a severable membrane and including also cuttingmeans carried in the receptacle opposite said top to sever the membraneupon rotation of the container neck within the receptacle.

7. Apparatus according to claim 1 in which said agent-introducing meansincludes a supply of the agent disposed in an elongated container, saidcontainer being mounted vertically on the top wall of said chamber in amanner to have a lower container portion submerged in water periodicallycirculated through the chamber and out of contact with water when watercirculation ceases and an upper container portion above the water as acontinuation of the lower portion, said submerged container portionhaving a water-passing aperture permitting dissolution and dispersal ofagent from said lower container portion, the agent in said upper portionbeing arranged to descend by gravity to continually replace dissolvedand dispersed agent in the the lower portion.

8. Apparatus according to claim 7 in which said container extendsthrough the chamber top wall and including also cooperating means onsaid container and wall securing said container to said wall invertically adjustable relation.

9, Apparatus according to claim 8 in which said container has avertically extended externally threaded portion to be thread adjustablerelative to said chamber top wall.

10. In combination a swimming pool, a water recirculation system for theswimming pool including a pump, a filter and conduit forming arecirculation loop between the pool, the pump and the filter; and flowconnected across said pump: apparatus for sanitizing the swimming poolwater which includes a mixing chamber having an inlet port and arelatively lower outlet port all above said swimming pool, meansperiodically operating the pump to circulate pool water through themixing chamber including tubing flow connecting the chamber inlet portwith the discharge side of the pump to the chamber through said inletport and tubing flow connecting the chamber outlet port to the suctionside of the pump, a sanitizing agent supply above water in the mixingchamber and means controllably introducing said agent into water thencirculating through the mixing chamber in response to periodic rise andfall of water in the chamber at the beginning and end of periodic pumpcirculation of the water to add sufficient agent to sanitize the poolbetween periodic pump circulations, and two independent valve means inthe chamber separately controlling waterflow through the inlet andoutlet ports including a first float-controlled inlet valve operative tolimit the water level in the mixing chamber during water circulationthrough the chamber and a second float-controlled outlet valve operativeto maintain the outlet open to permit complete gravity draining of waterfrom the chamber prior to closing the outlet upon cessation of waterpumping.

11. Apparatus for sanitizing swimming pool water which inciudes a mixingchamber having an inlet port and a relatively lower outlet port allabove the swimming pool to be sanitized, means periodically circulatingpool water through the chamber including a pump and conduit leading toand from the pool, said circulating means introducing water from theconduit on the discharge side of the pump to the chamber through saidinlet port and withdrawing water from the chamber through the outletport to conduit on the suction side of the pump, means introducing ametered quantity of normally solid water-soluble sanitizing agent intosaid Chamber in response to periodic water circulation through thechamber for mixing with circulating water at the onset of the watercirculation period, valve means in the chamber separately controllingwaterflow through the inlet and the outlet, said valve means including afloat-controlled outlet valve operative to maintain the outlet open topermit substantially complete gravity draining of water from the chamberfollowing termination of the water circulation period.

12. Apparatus for periodically sanitizing circulating swimming poolwater including a mixing chamber adapted to contain a continuouslycirculating body of pool water at relatively higher levels duringcirculation periods and relatively lower levels between such periods, asanitizing agent supply to the chamber and means supporting thesanitizing agent at a level within the chamber to be at least partlyimmersed in said pool water body during said water circulation periodsand not so immersed between such periods.

13. Apparatus according to claim 12 in which said chamber is providedwith an inlet port and an outlet port and including also valve meanscontrolling waterflow through said ports to define said water levels.

14. Apparatus according to claim 13 in which said outlet valve is floatcontrolled to permit substantially complete gravity draining of waterfrom the chamber.

UNITED STATES PATENT OFFICE CERTIFICATE OF COEC'HQN Patent No. 3,638,833Dated February 1, 1972 lnventor(s) Robert S. Lucas It is certified thaterror appears in the above-identified patent and that said LettersPatent are hereby corrected as shown below:

Column 3, line 36; the inlet port 22 has an internally threaded collar27 which" should read the inlet port fitting 22 has an internallythreaded collar 27 which Column 7, line 15; closing the outlet uponcessation of water pumping." should read closing the outlet valve uponcessation of water pumping.-

Signed and sealed this 20th day of June 1972.

(SEAL) Attest:

EDWARD M.FLETCHER, JR. ROBERT GOTTSCHALK Attesting Officer Commissionerof Patents ORM PO-105O (10-69) USCOMM-DC 5O376-P69 U.S. GOVERNMENTPRINTING OFFICE I969 0-366-334

1. Apparatus for sanitizing swimming pool water which includes a mixingchamber having an inlet port and a relatively lower outlet port allabove the swimming pool to be sanitized, means periodically circulatingpool water through the chamber including a pump and conduit leading toand from the pool, said means circulating water from conduit on thedischarge side of the pump to the chamber through said inlet portthrough said chamber and through the outlet port to conduit on thesuction side of the pump, means introducing a metered quantity ofnormally solid, water-soluble sanitizing agent into said chamber inresponse to periodic water circulation through the chamber for mixingwith water at the onset of the water circulation period to dissolve saidagent in water circulating through said chamber, two independent valvemeans in the chamber separately controlling waterflow through the inletand outlet ports including a first float-controlled inlet valveoperative to limit the level of water in the chamber during watercirculation periods and a second float-controlled outlet valve operativeto maintain the outlet open to permit substantially complete gravitydraining of water from the chamber following termination of the watercirculation period and thereafter to close the outlet valve. 2.Apparatus according to claim 1 in which said agent-introducing meansincludes a supply chamber containing a supply of the agent and having abottom opening vertically spaced above the mixing chamber, a meteringcup open to and below the supply chamber opening and having a bottomopening vertically below the supply chamber opening, valve means movablebetween said openings to sequentially communicate the supply chamberwith the metering cup and the metering cup with the mixing chamber todeliver metered amounts of agent from the supply to the mixing chamber,said valve means comprising a pair of valve members vertically spaced adistance to be movable into alternate blocking relation with one or theother of said bottom openings, and float means in said mixing chamberconnected to said valve members to raise or lower said valve membertogether in response to water level changes in said mixing chamber tofirst change the metering cup from the supply chamber at the onset ofthe water circulation period and to empty the metering cup into themixing chamber following the water circulation period and after waterhas substantially completely drained therefrom.
 3. Apparatus accordingto claim 2 including also a resilient annular seal in each of saidbottom openings and in which said valve means includes a cylindricalvalve body having oppositely tapered upper and lower ends defining saidvalve members, said body having a diameter to slidably engage saidseals.
 4. Apparatus according to claim 3 in which said float means isalso operatively connected to said outlet valve.
 5. Apparatus accordingto Claim 4 including also an agent supply container and means carried onsaid supply chamber mounting said container to empty into said supplychamber, said mounting means including an upwardly opening receptacle ontop of said chamber adapted to receive the neck of an inverted supplycontainer.
 6. Apparatus according to claim 5 in which said agent supplycontainer has a top comprising a severable membrane and including alsocutting means carried in the receptacle opposite said top to sever themembrane upon rotation of the container neck within the receptacle. 7.Apparatus according to claim 1 in which said agent-introducing meansincludes a supply of the agent disposed in an elongated container, saidcontainer being mounted vertically on the top wall of said chamber in amanner to have a lower container portion submerged in water periodicallycirculated through the chamber and out of contact with water when watercirculation ceases and an upper container portion above the water as acontinuation of the lower portion, said submerged container portionhaving a water-passing aperture permitting dissolution and dispersal ofagent from said lower container portion, the agent in said upper portionbeing arranged to descend by gravity to continually replace dissolvedand dispersed agent in the the lower portion.
 8. Apparatus according toclaim 7 in which said container extends through the chamber top wall andincluding also cooperating means on said container and wall securingsaid container to said wall in vertically adjustable relation. 9.Apparatus according to claim 8 in which said container has a verticallyextended externally threaded portion to be thread adjustable relative tosaid chamber top wall.
 10. In combination a swimming pool, a waterrecirculation system for the swimming pool including a pump, a filterand conduit forming a recirculation loop between the pool, the pump andthe filter; and flow connected across said pump: apparatus forsanitizing the swimming pool water which includes a mixing chamberhaving an inlet port and a relatively lower outlet port all above saidswimming pool, means periodically operating the pump to circulate poolwater through the mixing chamber including tubing flow connecting thechamber inlet port with the discharge side of the pump to the chamberthrough said inlet port and tubing flow connecting the chamber outletport to the suction side of the pump, a sanitizing agent supply abovewater in the mixing chamber and means controllably introducing saidagent into water then circulating through the mixing chamber in responseto periodic rise and fall of water in the chamber at the beginning andend of periodic pump circulation of the water to add sufficient agent tosanitize the pool between periodic pump circulations, and twoindependent valve means in the chamber separately controlling waterflowthrough the inlet and outlet ports including a first float-controlledinlet valve operative to limit the water level in the mixing chamberduring water circulation through the chamber and a secondfloat-controlled outlet valve operative to maintain the outlet open topermit complete gravity draining of water from the chamber prior toclosing the outlet upon cessation of water pumping.
 11. Apparatus forsanitizing swimming pool water which includes a mixing chamber having aninlet port and a relatively lower outlet port all above the swimmingpool to be sanitized, means periodically circulating pool water throughthe chamber including a pump and conduit leading to and from the pool,said circulating means introducing water from the conduit on thedischarge side of the pump to the chamber through said inlet port andwithdrawing water from the chamber through the outlet port to conduit onthe suction side of the pump, means introducing a metered quantity ofnormally solid water-soluble sanitizing agent into said chamber inresponse to periodic water circulation through the chamber for mixingwith circulating water at the onset of tHe water circulation period,valve means in the chamber separately controlling waterflow through theinlet and the outlet, said valve means including a float-controlledoutlet valve operative to maintain the outlet open to permitsubstantially complete gravity draining of water from the chamberfollowing termination of the water circulation period.
 12. Apparatus forperiodically sanitizing circulating swimming pool water including amixing chamber adapted to contain a continuously circulating body ofpool water at relatively higher levels during circulation periods andrelatively lower levels between such periods, a sanitizing agent supplyto the chamber and means supporting the sanitizing agent at a levelwithin the chamber to be at least partly immersed in said pool waterbody during said water circulation periods and not so immersed betweensuch periods.
 13. Apparatus according to claim 12 in which said chamberis provided with an inlet port and an outlet port and including alsovalve means controlling waterflow through said ports to define saidwater levels.
 14. Apparatus according to claim 13 in which said outletvalve is float controlled to permit substantially complete gravitydraining of water from the chamber.